The man was arrested at the school Friday, a day after a parent told police that a student discovered a cellphone recording inside a campus locker room.
The student and several classmates found the phone recording them while changing, police said.
"The students stopped the recording, deleted the video, and gave the phone to a teacher," police said.
Tracy Unified School District placed the coach on leave pending the outcome of the investigation, according to police.
"Our children deserve to feel safe at school and in every space where they should be able to learn, grow, and simply be kids," Tracy Police Chief Sekou Millington said on social media. "We are grateful to the students who brought this incident to the attention of adults and to the officers and detectives who acted quickly to investigate."
The investigation is continuing.
Anyone with information was asked to contact Detective Brian Cockey at Brian.Cockey@TracyPD.com or 209-831-6602 or Detective Joseph Bourassa at Joseph.Bourassa@TracyPD.com or 209-831-6969.
Anonymous tips may also be submitted by calling the Tracy Police Department Tip Line at 209-831-6TIP or by emailing TracyCrimeStoppers@TracyPD.com.
EDITOR'S NOTE: The suspect has not been identified in this story since they have not been arraigned in court